Angle B is 45% of angle A. Angle C is 35% of angle A. What is the measurement of angle A?

We assume, A, B, and C are angles of a triangle.

The sum of angles of a triangle is equal to 180º; therefore:

A+B+C=180º

B is 45% of angle A; then B=0.45A

C is 35% of anble A; Then C=0.35A

We can suggest this equation;

A+0.45A+0.35A=180

1.8A=180

A=180/1.8

A=100

Answer: The measurement of angle A is 100º.